Hyperthyroidism is a condition where the thyroid gland produces too much thyroid hormone. This can lead to an increase in metabolism, causing symptoms like weight loss, rapid heartbeat, and anxiety. People with hyperthyroidism may also experience heat intolerance and excessive sweating, making everyday activities uncomfortable. The most common cause of hyperthyroidism is an autoimmune disorder called Graves' disease. This condition causes the immune system to mistakenly attack the thyroid, leading to overproduction of hormones. Treatment options include medications, radioactive iodine therapy, or sometimes surgery to remove part of the thyroid gland, helping to restore hormone balance.